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<title>Debugging with GDB: TUI Overview</title>

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<a name="TUI-Overview"></a>
<div class="header">
<p>
Next: <a href="TUI-Keys.html#TUI-Keys" accesskey="n" rel="next">TUI Keys</a>, Up: <a href="TUI.html#TUI" accesskey="u" rel="up">TUI</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="TUI-Overview-1"></a>
<h3 class="section">25.1 TUI Overview</h3>

<p>In TUI mode, <small>GDB</small> can display several text windows:
</p>
<dl compact="compact">
<dt><em>command</em></dt>
<dd><p>This window is the <small>GDB</small> command window with the <small>GDB</small>
prompt and the <small>GDB</small> output.  The <small>GDB</small> input is still
managed using readline.
</p>
</dd>
<dt><em>source</em></dt>
<dd><p>The source window shows the source file of the program.  The current
line and active breakpoints are displayed in this window.
</p>
</dd>
<dt><em>assembly</em></dt>
<dd><p>The assembly window shows the disassembly output of the program.
</p>
</dd>
<dt><em>register</em></dt>
<dd><p>This window shows the processor registers.  Registers are highlighted
when their values change.
</p></dd>
</dl>

<p>The source and assembly windows show the current program position
by highlighting the current line and marking it with a &lsquo;<samp>&gt;</samp>&rsquo; marker.
Breakpoints are indicated with two markers.  The first marker
indicates the breakpoint type:
</p>
<dl compact="compact">
<dt><code>B</code></dt>
<dd><p>Breakpoint which was hit at least once.
</p>
</dd>
<dt><code>b</code></dt>
<dd><p>Breakpoint which was never hit.
</p>
</dd>
<dt><code>H</code></dt>
<dd><p>Hardware breakpoint which was hit at least once.
</p>
</dd>
<dt><code>h</code></dt>
<dd><p>Hardware breakpoint which was never hit.
</p></dd>
</dl>

<p>The second marker indicates whether the breakpoint is enabled or not:
</p>
<dl compact="compact">
<dt><code>+</code></dt>
<dd><p>Breakpoint is enabled.
</p>
</dd>
<dt><code>-</code></dt>
<dd><p>Breakpoint is disabled.
</p></dd>
</dl>

<p>The source, assembly and register windows are updated when the current
thread changes, when the frame changes, or when the program counter
changes.
</p>
<p>These windows are not all visible at the same time.  The command
window is always visible.  The others can be arranged in several
layouts:
</p>
<ul>
<li> source only,

</li><li> assembly only,

</li><li> source and assembly,

</li><li> source and registers, or

</li><li> assembly and registers.
</li></ul>

<p>A status line above the command window shows the following information:
</p>
<dl compact="compact">
<dt><em>target</em></dt>
<dd><p>Indicates the current <small>GDB</small> target.
(see <a href="Targets.html#Targets">Specifying a Debugging Target</a>).
</p>
</dd>
<dt><em>process</em></dt>
<dd><p>Gives the current process or thread number.
When no process is being debugged, this field is set to <code>No process</code>.
</p>
</dd>
<dt><em>function</em></dt>
<dd><p>Gives the current function name for the selected frame.
The name is demangled if demangling is turned on (see <a href="Print-Settings.html#Print-Settings">Print Settings</a>).
When there is no symbol corresponding to the current program counter,
the string <code>??</code> is displayed.
</p>
</dd>
<dt><em>line</em></dt>
<dd><p>Indicates the current line number for the selected frame.
When the current line number is not known, the string <code>??</code> is displayed.
</p>
</dd>
<dt><em>pc</em></dt>
<dd><p>Indicates the current program counter address.
</p></dd>
</dl>

<hr>
<div class="header">
<p>
Next: <a href="TUI-Keys.html#TUI-Keys" accesskey="n" rel="next">TUI Keys</a>, Up: <a href="TUI.html#TUI" accesskey="u" rel="up">TUI</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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